Effects of Simulated Sonic Booms on the Hatchability of White Leghorn ChickenEggs

摘要

Eggs of domestic white leghorn chickens were exposed to simulated sonic booms inthe Sonic Boom Test Facility at BBN Systems and Technologies in Canoga Park CA. Two-hundred and fifty-two fertile eggs in four groups were exposed to booms with levels of 3 psf (group A), 20 psf (group B), 0 psf (control group C) and 30 psf (group D). Ten exposures were given daily separated by 10 sec intervals (day 2-19 of incubation). Chicks were held for four days after hatching for observation. By chance, the mean egg weight at laying of groups A and C differed from groups B and D. Differences in survivorship among the groups during incubation were explained by this difference, with survivorship significantly lower in the least exposed groups (A and C; Time series analysis, Mantel-Cox criterion; c2 = 5.67; df = 1,245; p < 0.05). Final counts of the numbers of eggs pipped and hatched did not differ (c2=1.21; df= 3; p >/= 0.05), nor did weekly weights and weight at hatching (ANOVA, p > 0.05). None of the exposed eggs cracked during exposure and all chicks hatched were normal. Resonance frequencies of 23 chicken eggs ranged between 468 and 1036 Hz, and of4 quail eggs between 1274 and 1475 Hz, 6-7 octaves above the peak energy in the simulated sonic booms.